The object of this proposal is to undertake studies of nutritional requirements of aging individuals. These studies are to be carried out under strict control in the human nutrition laboratory in the Department of Nutritional Sciences at the University of California, Berkeley. The primary areas to be investigated are the requirements for protein, energy, protein-energy interrelationships, calcium, calcium-protein interrelationships and the trace minerals, iron, copper and zinc. The techniqus to be utilized are those which have been developed previously in our laboratory and applied to healthy human individuals. In view of the markedly increasing number of older individuals in our society, and the burden they place on society by increased incidence of illness associated with the aging process, the possible role of nutrition in alleviating and/or preventing many of these complications is a crucial one and makes these over-due studies of paramount importance.